tty/serial: atmel_serial: add device tree support

Will use aliases to enumerate ports, if available.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/atmel_serial.c

@@ -33,6 +33,8 @@
 #include <linux/sysrq.h>
 #include <linux/tty_flip.h>
 #include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/atmel_pdc.h>
 #include <linux/atmel_serial.h>
@@ -163,6 +165,16 @@ static unsigned long atmel_ports_in_use;
 static struct console atmel_console;
 #endif
 
+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_serial_dt_ids[] = {
+	{ .compatible = "atmel,at91rm9200-usart" },
+	{ .compatible = "atmel,at91sam9260-usart" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_serial_dt_ids);
+#endif
+
 static inline struct atmel_uart_port *
 to_atmel_uart_port(struct uart_port *uart)
 {
@@ -1411,6 +1423,48 @@ static struct uart_ops atmel_pops = {
 #endif
 };
 
+static void __devinit atmel_of_init_port(struct atmel_uart_port *atmel_port,
+					 struct device_node *np)
+{
+	u32 rs485_delay[2];
+
+	/* DMA/PDC usage specification */
+	if (of_get_property(np, "atmel,use-dma-rx", NULL))
+		atmel_port->use_dma_rx	= 1;
+	else
+		atmel_port->use_dma_rx	= 0;
+	if (of_get_property(np, "atmel,use-dma-tx", NULL))
+		atmel_port->use_dma_tx	= 1;
+	else
+		atmel_port->use_dma_tx	= 0;
+
+	/* rs485 properties */
+	if (of_property_read_u32_array(np, "rs485-rts-delay",
+					    rs485_delay, 2) == 0) {
+		struct serial_rs485 *rs485conf = &atmel_port->rs485;
+
+		rs485conf->delay_rts_before_send = rs485_delay[0];
+		rs485conf->delay_rts_after_send = rs485_delay[1];
+		rs485conf->flags = 0;
+
+		if (rs485conf->delay_rts_before_send == 0 &&
+		    rs485conf->delay_rts_after_send == 0) {
+			rs485conf->flags |= SER_RS485_RTS_ON_SEND;
+		} else {
+			if (rs485conf->delay_rts_before_send)
+				rs485conf->flags |= SER_RS485_RTS_BEFORE_SEND;
+			if (rs485conf->delay_rts_after_send)
+				rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
+		}
+
+		if (of_get_property(np, "rs485-rx-during-tx", NULL))
+			rs485conf->flags |= SER_RS485_RX_DURING_TX;
+
+		if (of_get_property(np, "linux,rs485-enabled-at-boot-time", NULL))
+			rs485conf->flags |= SER_RS485_ENABLED;
+	}
+}
+
 /*
  * Configure the port from the platform device resource info.
  */
@@ -1420,6 +1474,14 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 	struct uart_port *port = &atmel_port->uart;
 	struct atmel_uart_data *pdata = pdev->dev.platform_data;
 
+	if (pdev->dev.of_node) {
+		atmel_of_init_port(atmel_port, pdev->dev.of_node);
+	} else {
+		atmel_port->use_dma_rx	= pdata->use_dma_rx;
+		atmel_port->use_dma_tx	= pdata->use_dma_tx;
+		atmel_port->rs485	= pdata->rs485;
+	}
+
 	port->iotype		= UPIO_MEM;
 	port->flags		= UPF_BOOT_AUTOCONF;
 	port->ops		= &atmel_pops;
@@ -1433,7 +1495,7 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 
 	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
 
-	if (pdata->regs) {
+	if (pdata && pdata->regs) {
 		/* Already mapped by setup code */
 		port->membase = pdata->regs;
 	} else {
@@ -1450,10 +1512,6 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
 		/* only enable clock when USART is in use */
 	}
 
-	atmel_port->use_dma_rx	= pdata->use_dma_rx;
-	atmel_port->use_dma_tx	= pdata->use_dma_tx;
-	atmel_port->rs485	= pdata->rs485;
-
 	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
 	if (atmel_port->rs485.flags & SER_RS485_ENABLED)
 		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
@@ -1718,17 +1776,21 @@ static int atmel_serial_resume(struct platform_device *pdev)
 static int __devinit atmel_serial_probe(struct platform_device *pdev)
 {
 	struct atmel_uart_port *port;
+	struct device_node *np = pdev->dev.of_node;
 	struct atmel_uart_data *pdata = pdev->dev.platform_data;
 	void *data;
 	int ret = -ENODEV;
 
 	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
 
-	if (pdata)
-		ret = pdata->num;
+	if (np)
+		ret = of_alias_get_id(np, "serial");
+	else
+		if (pdata)
+			ret = pdata->num;
 
 	if (ret < 0)
-		/* port id not found in platform data:
+		/* port id not found in platform data nor device-tree aliases:
 		 * auto-enumerate it */
 		ret = find_first_zero_bit(&atmel_ports_in_use,
 				sizeof(atmel_ports_in_use));
@@ -1827,6 +1889,7 @@ static struct platform_driver atmel_serial_driver = {
 	.driver		= {
 		.name	= "atmel_usart",
 		.owner	= THIS_MODULE,
+		.of_match_table	= of_match_ptr(atmel_serial_dt_ids),
 	},
 };